Sigma 24-70mm 2.8 HSM for D7000

I currently do not have any lens for my camera. I wasn't too fond of the 18-105mm kit lens and sold it. I'm thinking of purchasing a Sigma 24-70mm 2.8 hsm for my D7000 because I like to take lowlight/ indoor pictures. I wish I can get the Nikon 17-55mm, but its out of my price range. I like to know if anyone has experience using this lens (on any camera) or using this lens with a D7000 (preferrably). How's the performance of the lens, its built and sharpness of the picture. For sure Nikon will top this but as a photography enthusiast is it worth it? Needs your thoughts on this. Thanks in advance.